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,b <br /> '' !m DIETZGI N'S RAILROAD CURVE <br /> ' - ✓:"rte/i i7 � � � � <br /> AND <br /> REDUCTION TABLES <br /> a <br /> 2s- uA Coyyrlaht,1914.by Eugene Dieter Co.,New York Clts <br /> PC T <br /> P <br /> d�4 <br /> s ,.sr kw tiu�o/- o 16–/ 6 <br /> --- <br /> zkz � doe b�-u1t Or <br /> 3 a <br /> i U CURVE FORMULAS <br /> �' `� � 9 �� �' \ I ,• ius�R--e1b ;(1)Degree of Curve=D and sing�=a(� <br /> Tangent=T=Rtan3 (3)Length of Curve=L=10 D(4) <br /> �. <br /> Middle ordinate=M=R(1—cos. j)(5) =Rvers 3(6) <br /> i Y E�tel�sl-=E=Ttan`-(7)=It -R(8)=Rexaec#(9) <br /> N L <br /> 4 4 Yong Chord-C=2 R sin.42 (10)&=Central Angle <br /> EXPLANATION AND USE OF TABLES <br /> �"S oos.--Given P. I.—Sta. 161+60.35 to find Sta. of P. C. <br /> uad�P.T. &—Or 10' Dom'20'. From Table IV for 1° curve T= 1 <br /> 1'amd+8% 14.49 ft. From Table V correction-,36 or T— <br /> elf g d 1 L ft,PP. C.�8 P.I.—T=157+45.50. Also from (4) L= <br /> f 4 2 2 ® 6 T,—Sta.P.C.+L=164-{-91.50. <br /> P. <br /> -Tangent 'offset$ vary.(approximately) directly with <br /> 4 I 't 1 8 o a 2 �) square the diatauce. Thus tangent offset for Stn. <br /> r abpv�urge is 2.16 ft.found as follows. From Table III tangent <br /> S r ', for 1 ft.=7.27 ft. Distance=158-8tn.P. C.=54.50,hence <br /> 7.27 (54.50+100)0=2.16 ft. Also square of any distance <br /> i j p i by twice the radius equals(approximately)the distance from <br /> J # bent to curve. Thus (54.50)2+(2 x 688.26)=2.16 ft. <br /> 4 v I#ageelioaa.—Defiection angle=% D for 100 ft., i/,1 <br /> 0 D for 50 ft., <br /> For o ft..—On minutes) 3 x C x D°or=deft.for 1 ft.from Table <br /> 4 ,or=2.60 x 81.5=136.2'fro T blame III. For eta. 159 de8ee- <br /> - a) angle=2"18.2'+8•W+2=°26.2,etc. <br /> Xxteras>s.—May be found in similar manner to tangents. 'Thus <br /> s for curve above is 91.$7. For from Table N 60 <br /> for 1°curve E=9 .6 <br /> s uj 5 ' fqe,V 20'=W.6+8%=91.27 and from Table V eorrection=.10 or <br /> 1 _ �'it. Or suppose 0-=32°and E i$measured and found to be <br /> Z� 7 ? � <br /> .-Wliat is D? From Tabic IV Ed]50.9 and+42=-5.5 or D� <br /> FIE <br /> K 82 <br />